Vibro-meter VM600 Comprehensive Machinery Protection and Condition Monitoring System

5. VM600 TACH (Tachometer Module)

• Description: A specialized module for measuring rotational speed, phase angle, and rotor position. It is critical for balancing and tracking orders.

• Key Parameters:

• Speed (1X RPM).

• Phase reference (Zero position).

• Rotor acceleration/deceleration rate.

• Input Channels: 4 independent channels (accepts magnetic pickups, prox probes, or digital TTL/HTL signals).

• Measurement Range: 0.1 RPM to 99,999 RPM.

• Functions:

• Output: Analog voltage or current proportional to speed.

Application Scenarios

The VM600 is versatile and is deployed across industries where machinery uptime and safety are critical:

1. Oil & Gas (Upstream & Downstream):

• Critical Compressors: Monitoring axial and radial shaft vibration on centrifugal compressors used in gas reinjection or pipelines.

• Turbines: Gas turbines used for power generation or mechanical drives.

• Pumps: Critical barrel pumps and injection pumps.

2. Power Generation:

• Steam Turbines: Large utility turbines require monitoring of eccentricity, differential expansion, thrust position (axial displacement), and bearing vibration.

• Hydro Turbines: Monitoring guide bearing vibration and shaft runout.

• Generators: Monitoring core vibration and bearing temperatures (via temperature module inputs).

3. Petrochemical & Chemical Processing:

• Centrifuges & Blowers: High-speed machinery where imbalance can develop quickly.

• Reactors & Agitators: Monitoring the mechanical health of large mixer drives.

4. General Industry:

• Paper Mills: Monitoring large steam rolls and dryer cans.

• Steel Mills: Monitoring large motors and rolling mill gearboxes.

Real-World Examples

Example 1: API 670 Compressor Skid Package

• Scenario: An engineering company designs a skid-mounted package containing a large centrifugal compressor driven by an electric motor for a natural gas pipeline station. The specifications require compliance with API 670 for machinery protection.

• VM600 Application:

• Slot 1: CMSS for Ethernet communication to the plant DCS.

• Slot 2: RPS6u configured for Radial Vibration (X and Y probes on two bearings). It provides the “Danger” trip relays that shut down the compressor if vibration exceeds 5 mils (127 microns).

• Slot 3: RPS6u configured for Axial Displacement (Thrust position) and Thrust Bearing Temperature. This protects the rotor from catastrophic axial shift.

• Configuration: One VM600 MPC4 rack is mounted on the compressor skid.

• Modules:

• Outcome: The compressor operates safely. During a surge event, the RPS6u detects the high vibration almost instantly and trips the machine. The data logged in the CMSS helps engineers analyze the surge profile to prevent future occurrences.

Example 2: Steam Turbine Condition Monitoring in a Power Plant

• Scenario: A power plant wants to upgrade their monitoring on a 50MW steam turbine. They need not only protection but also detailed data to predict maintenance needs (Predictive Maintenance) rather than just reacting to failures.

• VM600 Application:

• The racks utilize ISM4 modules instead of standard RPS6u.

• Configuration: Two VM600 racks are used in the control room.

• Modules:

• Detailed Monitoring: The ISM4 modules are connected to the bearing vibration probes. They continuously stream high-resolution vibration waveforms and FFT spectrums to the plant’s server using the OPC UA protocol via the CMSS.

• Outcome: Operators notice a gradual increase in the 1x RPM amplitude (unbalance) and the emergence of a 2x harmonic (misalignment) in the spectrum over three months. Because the VM600 provided this trend data, maintenance scheduled a shutdown during a low-demand period to realign the coupling and balance the rotor, avoiding an unplanned forced outage that could have cost millions in lost generation.

Example 3: Main Shaft Line Monitoring on a Marine Vessel

• Scenario: A LNG carrier vessel requires monitoring of its main propulsion engine and the intermediate shaft line. The environment is harsh (vibration, humidity, space constraints).

• VM600 Application:

• Configuration: VM600 MPC4 racks are chosen for their ruggedness (conformal coating) and compact size.

• Modules: A combination of RPS6u (for engine protection) and TACH modules.

• Function: The TACH module monitors the RPM of the main shaft to provide overspeed protection. The RPS6u monitors the gearbox vibration.

• Outcome: During rough seas, the system distinguishes between transient vibration caused by propeller emergence (which is harmless) and actual mechanical faults. The reliability of the VM600 ensures the vessel’s crew can focus on navigation without worrying about false machinery trips.